The commonly-seen industrial tooling machines, such as grinders, are normally driven pneumatically or electrically, with dust generated in operation. In addition to affecting operation and polluting environment, dust may be sucked into the tooling machine and accumulated thereinside. In the long run, the accumulated dust would affect the function of the tooling machine. Therefore, some manufacturers have proposed technologies to solve the abovementioned problems, such as the technologies disclosed in Taiwan patent No. 1267426 and Taiwan patent publication No. 200838641.
The Taiwan patent No. I267426 disclosed a grinder with a dust-resistant function, which comprises a body, a rotary shaft, a driving module, a bottom cover and a sealing element. The bottom of the body is concaved inward to form a space where the driving module is accommodated. The rotary shaft is vertically coupled to the driving module and driven by the driving module. The lower end of the rotary shaft has a plane facing downward. The bottom cover has a through-hole at the center thereof and covers the bottom of the body to seal the space. The rotary shaft is aligned exactly to the through-hole. The plane is greater than the through-hole and positioned above the top surface of the bottom cover. The sealing element is disposed between the plane and the top surface of the bottom cover to seal the gap between the plane and the bottom cover. Therefore, the patent of No. I267426 achieves the dust-resistant effect via the sealability between bottom cover and the bottom of the body and the airtightness between the plane and the bottom cover.
The Taiwan patent publication No. 200838641 disclosed a grinder with a dust-resistant effect, which comprises a housing, a pneumatic cylinder and a sealing cover assembly. The pneumatic cylinder is disposed inside the housing and has a cylinder body and a driving shaft rotatably passing through the cylinder body. The driving shaft has a first coupling member penetrating the cylinder body. The sealing cover assembly has at least one sealing cover disposed inside the housing and surrounding the first coupling member of the driving shaft. The sealing cover has at least one flow channel interconnecting with the cylinder body for exhausting the air flow, whereby the air flow is dispelled from the perimeter of the first coupling member of the driving shaft. Therefore, the patent of No. 200838641 uses the air flow dispelled from the perimeter of the first coupling member to blow away dust and thus promotes the rotation smoothness of the driving shaft.
Although the abovementioned patents respectively proposed their dust-resistant schemes for different tooling machines, they did not pay attention to the dust-resistant design of shaft supporters (such as bearings), which are critical in operation. Thus, dust still may accumulate in the shaft supporter and affect the operation thereof. Suppose a cover is disposed corresponding to a shaft supporter to make the shaft supporter located in an isolated space. The operating dynamic module of the tooling machine applies pressure to the shaft supporter. The pressure will be exhausted to the isolated space. However, the pressure would be trapped in the isolated space and hard to leak out therefrom. Thus, the pressure makes the shaft supporter unable to operate effectively. The trapped pressure is exactly the factor making the manufacturers unable to provide dust-resistant designs for shaft supporters.
Accordingly, the Inventors are eager to develop a technical scheme to solve the abovementioned problems.